Liquid crystal display devices are widely used for display devices ranging from large-sized display devices such as television receivers to small-sized display devices such as mobile phones. Therefore, the development of liquid crystal display devices is intended to achieve cost reduction or to provide high-value added liquid crystal display devices. In recent years in particular, there has been a growing interest in global environment and thus, the development of liquid crystal display devices consuming less power has attracted attention.
As an example of a method for reducing power consumption sufficiently as well as satisfying the basic display qualities such as brightness and contrast, a driving method of a display device in which a scanning period and a non-scanning period which is longer than the scanning period are provided has been disclosed (see Patent Document 1). Specifically, in the above driving method of a display device, all data signal lines are electrically disconnected from a data signal driver in an inactive period where all scan lines and data signal lines are not selected, whereby a high-impedance state is made.